Number system converter

ABSTRACT

A number system converter is disclosed which includes two number systems coupled by a linking assembly. Each number system includes a number scale, an indicator and a slotted selector arm for aligning the indicator with a selected number on the number scale. The selector arms overlap each other and the linking assembly includes a guide member, a pin extending through the slots in the overlapping selector arms and the guide member, and a carriage for adjusting the position of the guide member.

United States Patent [191 lsaltsen [111 3,839,624 [451 Oct. 1, 1974 1 NUMBER SYSTEM CONVERTER [76] Inventor: William M. Isaksen, 37 Burlington Ave, Leonardo, NJ. 07748 [22] Filed: May 21, 1973 21 Appl. No.: 362,391

[52] US. Cl. 235/61 GM, 33/150, 33/192, 235/78 F [51] Int. Cl G06g 1/00 [58] lField olSearch.....235/61l3, 61 C, 61 E, 61 F, 235/61 PS, 65, 69, 77, 83, 85, 88, 61 GM, 78 F; 33/23 D, 150, 192

[ 5 6 References Cited UNITED STATES PATENTS 1,156,694 [0/1915 Kopinski 33/150 1,778,037 10/1930 Okey 235/61 GM 1,983,961 12/1934 Aranjo 235/61 GM 2,080,587 5/1937 Sinitain-White.... 235/61 B 2,096,032 10/1937 Engel 235/61 GM 2,621,855 12/1952 Hauser... 235/61 GM 2,716,521 8/1955 Brown 235/61 GM FOREIGN PATENTS OR APPLICATIONS 620,653 10/1935 Germany 235/61 GM 761,690 4/1954 Germany 235/61 F OTHER PUBLICATIONS Svoboda, Computing Mechanisms and Linkages," McGraw-Hill Book Co., New York, 1948, pp. 14-15.

Primary Examiner-Lawrence R. Franklin Attorney, Agent, or FirmMurphy, Springberg & Clapp 5 7] ABSTRACT A number system converter is disclosed which includes two number systems coupled by a linking assembly. Each number system includes a number scale, an indicator and a slotted selector arm for aligning the indicator with a selected number on the number scale. The selector arms overlap each other and the linking assembly includes a guide member, a pin extending through the slots in the overlapping selector arms and the guide member, and a carriage for adjusting the position of the guide member.

25 Claims, 11 Drawing Figures PAIENTEU 3.839.624

SREH 2W 5 PATENTEH 1 I974 SHEET 3 OF 6 PATENTED 1 974 arm w a g HIIIIII! 5 m2 5 3: N2 :1 Q: Q: Q:

1 NUMBER SYSTEM CONVERTER BACKROUND OF THE INVENTION 1. Field of the Invention This invention relates to techniques for converting the magnitude of a number in one system to its corresponding magnitude in another system and pertains in particular to mechanical converters.

2. Description of the Prior Art Occasions abound which call for the conversion of a number in one system to its counterpart in another system. A particularly common example is currency conversion. Many types of currency converters are available; i.e., table, graphs, calculators and the like, but all lack in some degree simplicity, convenience and versatility.

Accordingly, one object of this invention is to achieve a number system converter which is versatile, simple and convenient to use.

Of the many currency converters which are commercially available, small hand-held types are generally the most acceptable. Their usefulness, however, has been limited by their versatility. For example, if a small, hand-held currency converter can convert currency only at a fixed exchange rate, it loses much of its value when the exchange rate fluctuates.

Accordingly, another object of this invention is to achieve increased versatility in simple, ease to use, handheld currency converters.

SUMMARY OF THE INVENTION In accordance with a preferred embodiment of this invention, a particularly convenient converter is achieved by coupling two number systems with a linking assembly. Each number system includes a numerical scale, an indicator and a selector for aligning the indicator with a selected number on the numerical scale. The linking assemblyjoins the selectors in the two systems sothat movement of one selector produces movement of the other. Moreover, the selectors cooperate with the linking assembly so that the distance traveled by one will be a fixed multiple of the distance traveled by the other.

According to one feature of this invention, simplicity is achieved by restraining free movement of the linking assembly to a path disposed perpendicularly to a line joining the pivot points of the selectors.

According to another feature of this invention, simplicity is achieved by restricting travel of the moving ends of the selectors to parallel paths disposed perpendicularly to the path traveled by the linking assembly.

According to another feature of this invention, versatiltity is achieved by adjusting the position occupied by the linking assembly path between the paths traversed by the moving ends of the selectors.

A better understanding of these and other objects and features of the invention will be facilitated by reference to the drawing and detailed description which follow.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a plan view of a simplified version ofa converter made in accordance with this invention.

FIG. 2 is a rear plan view of the embodiment of the invention illustrated in FIG. 1. modified to take an alternate form.

FIG. 3 is an exploded view, taken in side elevation, of another alternate converter made in accordance with this invention.

FIG. 4 is an end elevation view of the converter illustrated in FIG. 3, but with all of the components assembled.

FIG. 5 is a side elevation view of the converter shown in FIG. 3 taken in section along the lines 5-5 in FIG. 4.

FIG. 6 is a fragmentary view of components of the converter shown in FIG. 3 taken in perspective and enlarged to illustrate interacting elements.

FIG. 7 is a plan view of another alternative embodi ment of a converter made in accordance with this in vention.

FIG. 8 is an end elevation view of the converter illustrated in FIG. 7.

FIG. 9 is a plan view of the converter illustrated in FIG. 8 taken in section along the line 99.

FIG. 10 is a rear plan view of the converter illustrated in FIG. 7.

FIG. 11 is an alternative form of the portion of the converter illustrated in FIG. 9.

DETAILED DESCRIPTION Referring to FIG. 1, a converter 10 is illustrated which comprises a linking assembly 11, two number systems coupled by the linking assembly 11 and a base 12 supporting the two number systems and the linking assembly 11.

The first number system includes a number scale 13 inscribed on the surface of the base 12, a selector arm 14 pivotally joined to the base 12 by a rivet l5 and an indicator window 16 located in the free end of the selector arm 14. The base 12 is conveniently made from a plastic material and the number scale 15 is disposed on the surface thereof so that it coincides with the path traveled by the indicating window 16 when the selector arm 14 pivots.

The selector arm 14 is advantageously made of a rigid material such as aluminum and is perforated by an elongated slot 17 and a short slot 18. The slot 17 accomodatcs a portion of the linking assembly 11, while the slot 18 cooperates with a drive assembly 19.

The drive assembly 19 imparts rotary movement to the selector arm 14 and is supported on the base 12 by two of three tabs 20. It includes a knob 21, a worm drive 22 and a drive block 23. The drive block 23 is tapped to accomodate the worm drive 22 and includes a drive pin 24 which engages the slot 18 in the selector arm 14. The drive block 23 is journaled to accomodate a slide rod described elsewhere in detail.

The second number system is similar to the first and includes a number scale 30 inscribed on the surface of the base 12, a selector arm 31 pivotally mounted on the base 12 by a rivet 32 and an indicator window 33 located in the free end of the selector arm 31. The number scale 30 is disposed on the base 12 so that it coincides with the path traveled by the indicator window 33 when the selector arm 31 pivots. The selector arm 31 is advantageously made of a rigid material such as aluminum and includes an elongated slot 34 for accomodating a portion of the linking assembly 11.

The linking assembly 11 joins the selector arms 14 and 31 and includes a link pin 37, a carriage assembly 38, a worm drive 39 and a slide rod 40. The carriage assembly 38 adjusts the relationship between the selector arms 14 and 31 and comprises a guide arm 41, an elongated guide slot 42 apertured in the guide arm 41 and a shoulder 43 journaled and tapped to accomodate the slide rod 40 and the worm drive 39, respectively. The worm drive 39 includes a knob 44 and is supported at each end by two of the tabs 20. It extends through the shoulder 43 so as to impart reciprocal movement to the carriage assembly 38 when the knob 44 is turned. The slide rod 40 is advantageously made of a rigid material such as aluminum and is supported by the same two tabs 20 wich support the worm drive 39.

As best seen in FIG. 1, the select arm 14, the select arm 31 and the guide arm 41 are joined by the link pin 37. Advantageously, the link pin 37 is a metal rivet and is attached so that it is free to slide in the slots 17, 34 and 42 when the various arms move.

The worm drive 39 and the slide rod 40 are disposed on the base 12 in parallel to each other and to an imaginary line joining the rivets 15 and 32. Consequently, when a position for the guide arm 41 is established, the guide slot 42 will define a path of travel for the link pin 37 with is coincident to an imaginary line lying perpendicular to and intersecting the imaginary line which joins the rivets 15 and 32. As will be better understood from the description of converter operation, readjustment of the point of intersection between the path of travel of the link pin 37 and the imaginary line joining the rivets 15 and 32 will change the multiplier which relates the respective distances traveled by the selector arms 14 and 31.

Before using, the converter must be calibrated. Calibration begins by rotating the knob 21 until the indicator window 16 on the selector arm 14 is aligned with a desired number on the number scale 13. Thereafter, the knob 44 is rotated until the selector arm 31 pivots the indicator window 33 into alignment with a number on the number scale 30 which, in the desired number system, corresponds to the first selected number.

Referring to FIG. 1, it will be noted that rotation of the knob 44 results in a lateral movement of the guide arm 41. Whe two corresponding numbers have been selected, however, further lateral movement of the guide arm 41 is unwanted. Consequently, subsequent number conversions are achieved merely by rotating the knob 21. As will be readily understood, rotation of the knob 21 limits movement of the components solely to relative movement between the two selector arms. By this technique, a specific ratio of movement is established between the two selector arms. As a result, the illustrated converter 10 can quickly be calibrated to convert between any two number systems.

A worm driven carriage for driving the selector arms has been illustrated, but it will be readily recognized that other driving mechanisms are contemplated. For example, the rivets or 32 could readily be combined with appropriate drive gears for imparting rotation to the selector arms. Moreover, the driving mechanisms can readily be delected and the guide slot 42 can be formed by perforating the face of the base 12. In this latter case, of course, the ratio between the number systems can not be changed after it is once set.

Referring to FIG. 2, two alternate number systems are disclosed. Each includes a number scale 50 and 51, respectively, and both are inscribed on the reverse of the base 12 in replacement of the number systems 13 and 30, respectively, as they appear in FIG. 1. In addition, the selector arms 14 and 31 have been modified soas to include wrap-around indicator flaps 52 and 53, respectively. With this arrangement, a scale multiplier 60 can advantageously be used.

A scale multiplier is especially convenient when the ratio between the two number systems is particularly large. A typical instance occurs when the converter 10 is used to convert between two currencies having a large exchange rate; i.e., between US. Dollars and Italian lira.

As shown in FIG. 2, the scale multiplier 60 comprises two cover plates 61 and 62, a slide bar 63 and two link arms 64 and 65 for coupling the slide bar 63 to the cover plates 61 and 62. The cover plates 61 and 62 are made of an opaque material such as plastic and each includes a guide slot 66 and 67, respectively, Each guide slot 66 and 67 cooperates with two lower guides 68 and 69, respectively. The guides 68 and 69 are affixed to the base 12 and each may advantageously comprise a bent-over flap. The lower guides 68 and 69 cooperate with two upper guides 70 and 71 which may also advantageously comprise bent-over flaps. Functionally, the upper and lower guides define paths of travel for the cover plates 61 and 62. Finally, the two cover plates 61 and 62 each include a connector post 72 and 73, respectively.

As best understood by reference to FIG. 2, the cover plate 61 and 62 adjust the magnitude of the digits displayed on the number scales so that the numbers will read in units, tens, hundreds or thousands, as desired.

In order to cover or uncover the zeros necessary to change the scale display, the cover plate 61 slides laterally between the lower and upper guides 68 and 70, while the cover plate 62 slides laterally between the guides 69 and 71.

The link arms 64 and 65 impart the necessary lateral sliding movement to cover plates 61 and 62, respectively, in response to a vertical sliding movement of the slide bar 63 as viewed in FIG. 2. The slide bar 63 is advantageously made of the same material as the cover plates and includes a connecting post 74 as well as two slots 75 and 76. The two slots 75 and 76 accomodate two rivets 77 and 78 which hold the slide bar 63 on the base 12 while simultaneously restraining vertical movement to a defined path.

The link arms 64 and 65 are advantageously made of the same material as the slide bar 63 and each includes a detent slot 79a and 7%, respectively. Both link arms 64 and 65 are attached to the slide bar 63 and the cover plate 61 and 62, respectively; i.e., the connector post 72 cooperates with the detent slot 79a to join the link arm 64 to the cover plate 61, the connector post 73 cooperates with the detent slot 79b to join the link arm 65 to the cover plate 62 and the connector post 74 joins both arms to the slide bar 63. Both link arms 64 and 65 are free to rotate, but neither can move laterally, with respect to the connector post 74. For purposes explained below, however, the detent slots 79a and 79b permit lateral as well as rotational movement of the ends of the link arms 64 and 65 not attached to the connector post 74.

Thescale multiplier 60, as it appears in FIG. 2, is in a multiplied condition-As shown,- the slide bar 63 is is in its uppermost position-Moreover, thecover plate 61 is cooperatingwith the number scale50 so that the exposed digits aredisplayed in tens. Similarly, the cover plate 62 is cooperating with the number scale 51 so that the exposed digitsare displayedin hundreds.

The scale multiplier v60 is returned to the unmultiplied position by slidingthe slide bar 63 down as viewedin FIG. 2. Asthe slide bar 63 moves, the link arms 64 and'65 spread and thereby urge thecover plates 6l .and '62'outwardly; Whemthe slide bar 63 reaches its-lowest point, eachcover plate Y61 and 62 will overlay a row of 'zeros. In the-unmultiplied position, therefore, thevnu-mber. 'scale'50 will read in units while the number scale 51-Iwill; readin-tens. Thus, by moving the slide bar'63 'upand down, the numbers displayed on the number scales 50 and "51 can be increased and decreased by a multiple of ten.

In the foregoingzarrangement, .theratio between the number scales is ten. That ratio, however, may readily be increased ordecreased. Asshown in FIG. 2, the, desired change iseffectedmerely'by' repositioning the connector posts 72-and 73-in the detent slots 79a and 79b; Forexample, shifting the,connecting post 73 so it occupies that 7 portion of the-detent 1 slot 79b furthest from the-slidersbar 63, as vie-wed .in-FIG. 2,.will reduce the ratio betweenthescales tounity. It willbe readily understood thatsimilaradjustments of'the relationship betweenzthedetent slots andtheconnector posts will produce. other. ratios.

Referring to FIG. 3, anotherembodiment-of the converter is illustrated. As 2 before, it comprises two number systems coupled-by alinking assembly 80 which ismounted on asupport plate 81..The first-numbersyst'emcomprises avgraduated diskscale182 coupled to a selector arm183iby. a:,sp ur gear 84 and a'curved rack gear 85. The spur. gearl84is attached to the disk scale 82'by ashaft'86, while-therack gear-85jislocated atone end of the selector arm 83;

The selector arm 83comprises two legs 87 joined at one end to form-a U-s'haped configuration. The rack gear 85 is located at the end of oneleg. 87, while the other end-is aperturedwith an elongatedslot 88. Each leg 87, where the'two comeitogether to form the bight of the U, is perforatedwithaa hole89. The two holes 89 are in register with each other and'line upwith a corresponding hole 90 in the support, plate 81 when the two legs 87 bracket the support plate 81. A rivet 91 joins the legs 87 to the support plate 81, while simultaneously serving. as a pivot point. As best seen in FIG. 3, the leg 87 which terminates in the rack gear 85 is also perforated with a short slot 92.

The second number system comprises a graduated disk scale 100- connected to aselector arm 101 by a spur gear 102 anda curved rack gear 103. As shown in FIG. 5, the spur gear 102 is attached to the disk scale 100 by a shaft 104, while the rack gear 103 is located at one end of the selector arm 101.

The selector arm 101 comprises two legs 105 joined at one end to form a U-shaped configuration. The rack gear 103 is located at the endv of one leg 105, while the otherend is apertured by a slot 106. Each leg 105 includes a hole 107 and the two holes 107 line up with a corresponding hole 108 in the supportplate 81 when the two legs 105 bracket the support plate 81.'A rivet 109 joins the two legs 105 to the support plate 81. while 6 simultaneously serving as a pivot point for the selector arm 101.

The linking assembly couples the selector arms 83 and 101 and includes a link pin 113 and a carriage 114. The carriage 114 acts as a calibrator and moves the selector arm 101 independently of the selector arm 83 under the influence of an adjusting member 115. The adjusting member 115 is disposed parallel to a slide rod 116 and is itselfa rod having a knurled knob 117 at one end and a worm drive 118 at the other end. As best seen in FIG. 3 and 5, two tabs 119 are bent up from the surface of the support plate 81 and both are journaled to accept and hold the adjusting member 115 and the slide rod 116.

The carriage 114 is advantageously made as a block; i.e., aluminum, and includes an elongated arm having an elongated guide slot 120 at one end and two ears 121 projecting from the other end. The two ears 121 are journaled and tapped to cooperate with the worm drive 118 on the adjusting arm 115.

The link pin 113 is advantageously a metal rivet which, as best seen in FIG. 5, couples the selector arm 83, the selector arm 101 and the carriage 114 by extending through their respective slots. Consequentlyfif the selector arm 83 is rotated, its movement will be transmitted to the selector 101 casuing it to rotate as well.

As best seen in FIG. 3, the selector arm 83 is rotated by a drive assembly 124. The drive assembly 124 includes a drive member 125 and a driven member 126. The driven member 126 is advantageously an aluminum block having two ears 127 journaled to slide on a rod 128. The rod 128 is supported between two tabs 129 which project from the support plate 81. In addition, the driven member 126 is drilled and tapped to accomodate a worm drive and, as shown. in FIG. 6, includes a projecting pin 130. As best seen from FIG. 6, the pin 130 engages the short slot 92 to transform translational-movement of the driven member 126 into rotation of the selector arm 83. The drive member 125 is an elongated rod which is supported between two tabs 131 on the support plate 81, and which includes a worm drive 132 at one end and a knurled knob 133 at the other end.

As best seen in FIGS. 3, 4 and 5, the entire converter assembly is conveniently housed in a case 136 which includes two indicator windows 137 and 138. The two windows are disposed so as to be in register with the numbers on the disk scales 82 and 100, respectively.

As before, the converter 10 must be calibrated before use. To do so, the knurled knob 133 is twisted so as to impart movement to the driven member 126 and its pin 130. The pin 130 bears in the short slot 92 and thereby causes the selector arm 83 to rotate around its rivet 91. As the selector arm 83 rotates, the rack gear 85 rotates the spur gear 84 which, in turn, rotates the disk scale 82. Twisting is continued until the desired number appears in the indicator window 137.

As will be understood from FIGS. 3 and 5, movement of the selector arm 83 slides the link pin 113 in the guide slot 120 and thereby causes the selector arm 101 to follow the rotation of the selector arm 83. The position occupied by the selector arm 101 when the selector arm 83 reaches its selected position, however, may not correspond to the desired ratio between scales. Consequently, calibration is completed by rotating the selector arm 101 until the disk scale 100 displays the desired corresponding number. Movement of the selector arm 101 is achieved by twisting the knob 117 so as to impart movement to the carriage 114. As the carriage 114 moves, it bears on the link pin 113 thereof causing it to move in the slots 88 and 106 of the selector arms 83 and 101, respectively, as well as the guide slot 120 in the carriage 114. Becasue of the friction in the drive assembly 124, the selector arm 83 remains stationary. The selector arm 101, however, is free to move, so movement of the link pin 113 imparts thereto a pivoting movement. As the selector arm 101 pivots, the curved rack gear 103 rotates the disk scale 100. Adjustment is continued until the number in the desired number system corresponding to the number appearing in the indicator window 137 appears in the indicator window 138. When it does, calibration is complete. Thereafter, conversion between scales is achieved merely by twisting the adjusting knob 133 until the desired number appears in the appropriate indicator window and then reading the corresponding number in the other indicating window.

As in the previousembodiment, a scale multiplier can be used to advantage. Referring to FIGS. 3, 4 and 5, a scale multiplier is illustrated which includes two buttons 140 and 141, and two cover plates 142 and 144. Each button 140 and 141 is linked to a cover plate by a shaft 145. As best seen in FIG. 4, the case 136 is slotted to accept both shafts 145. From FIG. 4, it can be recognized that the cover plates 142 and 143 are opaque flat strips disposed to cover and uncover successive rows of zeros inscribed on the surfaces of the scales 82 and 100.

As illustrated in FIGS. 4 and 5, the cover plate 143 is in its normal position so that only digits are displayed. The cover plate 142, however, is in a multiplier position. As a result, both digits and multiplying zeros are displayed. Thus, the disclosed arrangement has the effect of expanding the ratio between the numbers on the scales 82 and 100; i.e., so that numbers on the scale 100 are ten times greater than those on the scale 82. It will be recognized, however, that the cover plates can readily be adjusted to produce various multiplier ratios between the scales.

In another embodiment, as shown in FIGS. 7, 8, 9 and 10, a converter comprises two number systems 150 and 151, a linking assembly 152 for joining the two number systems and a base assembly 153 for supporting the other assemblies. As can be seen from FIGS. 7 and 8, the number systems 150 and 151 are located on the front of the base assembly 153, while, as shown in FIG. 10, the linking assembly 152 is located on the rear. As shown best in FIGS. 8 and 10, the base assembly 153 is essentially a flat metal or stiff plastic plate perforated by a pair of parallel tracks or slots 154 and having end walls notched out and folded inwardly to form a windowed enclousre.

Referringto FIGS. 7, 8 and 10, the number system 150 cooperates with an indicator assembly 158 and includes a disk 155, a selector assembly 156 and a drive assembly 157. The disk 155 and the indicator assembly 158 interact in response to actuation of the selector assembly 156 to select and display desired numbers. Operation of the selector assembly 156 occurs in response to actuation of the drive assembly 157.

The disk 155 is conveniently circular and may be advantageously made of an opaque plastic material. As best seen in FIG. 7, its outer rim is located under a win- 'dowed portion of the base assembly 153 and graduated and imprinted with appropriate digits. For multiplier purposes, each numerical digit has a number of associated zeros (not shown).

As best seen in FIGS. 8, 9 and 10, the selector assembly 156 includes a carriage 160 and a selector arm 161. The carriage 160 is advantageously made from a block of rigid material such as plastic and includes two guide pins 162 which engage and slide in one of the tracks or slots 154. As best seen in FIG. 10, one guide pin 162 engages an end of the selector arm 161.

The selector arm 161 is a rectangular member advantageously made of a plastic srip. It is attached to a drive block 163 located at the end engaged by the aforesaid guide pin 162, and has a U-shaped slot 164 located at the other end. As best seen in FIG. 8, the drive block 163 cooperates with the drive assembly 157 to impart rotationalmovement to the selector arm 161.

The drive assembly 157, as shown in FIGS. 8 and 10, includes a knurled knob 165 and a worm drive 166. The worm drive 166 extends away from the knob 165 and is supported between two tabs 167 projecting upwardly from the surface of the base assembly 153. The drive block 163 is tapped to accomodate the worm drive 166 and is jointly attached to the selector arm 161 and the carriage 160 through a guide pin 162. Consequently, when the knob 165 is twisted, the drive block 163 will simultaneously impart movement to the carriage 160 and the selector arm 161.

The carriage 160 is coupled so that its translational movement along a slot 154'will be converted into rotational movement of the disk 155. In the embodiment illustrated in FIG. 9, one edge of the carriage 160 is equipped with rack teeth 168, while the disk 155 includes a corresponding spur gear 169. Alterative couplings are contemplated. In FIG. 11, for example, a drum 170 projects from the disk 155 and is encircled by a line 171 having one end attached to a spring mechanism 172 and the other end looped around two pulley posts 173 and attached to the carriage 160.

Like the number system 150, the number system 151 cooperates with the indicator assembly 158 and, as illustrated in FIGS. 7, 9, and 10, comprises a disk 175 and a selector assembly 176. As in the number system 150, the disk 175 and the indicator assembly 158 interact in response to actuation by the selector assembly 176 so as to display desired numbers.

The disk 175 is conveniently circular and may advantageously be made of the same material as the disk 155. As best seen in FIG. 7, its outer rim is located under a windowed portion of the base assembly 153 and graduated and imprinted with appropriate digits. For multiplier purposes, each digit may have a number of associated zeros.

Referring to FIGS. 9 and 10, the selector assembly 176 includes a carriage 177 connected to a selector arm 178. The carriage 177 is advantageously made from a block of rigid material such as plastic and includes two guide pins 179 which engage and slide in the track or slot 154 which is opposite to the one occupied by the guide pins l62associated with the carriage 160. As can be seen from FIGS. 8, 9 and 10, one of the guide pins 179 rotatably engages the selector arm 178.

The selector arm 178 is advantageously made of the same material as the selector arm 161 and includes an elongated slot 180. The portion" of the selector arm 178 housing the slot 180 is rectangular in configuration and is dimensioned so as to slidably fit in the slot 164 of the selector arm 161.

If desired, however, the slots 164 and 180 can be extended to accomodate the guide pins 162 and 179. In that case, the selector arms 161 and 178 can be made as a single unitary member closed at both ends and having a single internal slot embracing the guide pins 162 and 169 and the link block 181.

As best seen in FIG. 10, the selector arms 161 and 178 are coupled by a link block 181 in the linking assembly 152. In addition to the link block 181, the linking assembly 152 includes a worm drive 182, a tab 183, a bridge 184 and a knurled knob 185. As shown in FIG. 10, the worm drive 182 is supported at opposite ends by the tab 183 and the bridge 184, respectively. Both the tab 183 and the bridge 184 are attached to the base assembly 153 and the bridge 184 is notched (not shown) to permit free passage of the selector arms 161 and 178. The knob 185 is attached to the end of, and the linking pin 181 is tapped to accomodate the threads on, the worm drive 182.

The link block 181 extends through the slot 180 and thereby forms the pivot point for the selector arms 161 and 178. Thus, when the selector arm 161 is moved at its end by the drive assembly 157; it will rotate around the link pin 181. Since the selector arm 178 is embraced by the slot 164, it will rotate proportionally to the rotation of the selector arm 161. Plainly, by moving the link block 181 translationally, the constant of proportionally between the ends of the selector arms 161 and 178 can readily be adjusted.

As best seen in FIGS. 9 and 10, when the selector arm 178 rotates, the associated guide pin 179 imparts translational movement to the carriage 177. As in its counterpart, the carriage 177 couples the disk 175 to the selector arm 178. In the embodiment illustrated in FIG. 9, one edge of the carriage 177 is equipped with rack teeth 186, while the disk 175 is equipped with a corresponding spur gear 187. ln'the alternative form shown in FIG. 11, the spur gear 187 is replaced by a drum 188 and coupling is achieved by a line 189 which wraps around the drum 188 and has one end attached to a spring mechanism 190 and the other end looped around two pulley posts 191 and attached to the carriage 177.

As in other embodiments, calibration begins by twisting the knob 165 until the disk 155 and the indicator assembly 158 cooperate to display a desired number in the first number system. Next, the knob 185 is rotated until the disk 175 and the indicator assembly 158 cooperate to display the desired corresponding number in a second number system. Thereafter, conversions are made between the two number systems by rotating the knob 165 until the desired number is displayed by one disk and then reading its corresponding counterpart on the other disk.

As best seen in FIG. 7, the indicator assembly 158 provides a multiplier function between the disks. The indicator assembly 158 comprises a bracket 194 and two cover plates 195. The bracket 194 is aperatured by two windows 196 and includes two detent slots 197. The two windows 196 are disposed in register with the scales on the disks 155 and 175, respectively, and the detent slots 197 accomodate buttons 198 for holding the cover plates 195 to the bracket 194.

As will be seen from FIG. 7, adjusting the position of the buttons 198 in the detent slots 197 introduces a multiplier factor between numbers on the two disks and 175. In the embodiment illustrated, the cover plate 195 which cooperates with the disk 155 has been adjusted so that numbers are displayed in units, while the cover plate 195 which cooperates with the disk has been adjusted so that numbers are displayed in tens. It will be readily recognized that other combinations can easily be achieved.

In summary, a converter has been disclosed which has features making it simple, convenient to use and highly versatile. While several embodiments of the invention have been disclosed, it will be apprecaited that they are merely illustrative of the principles of the invention and many other embodiments falling within its scope will readily occur to those skilled in the art.

What I claim is:

1. In a calculating device for converting numbers from one number system to another, the combination comprising:

first and second graduated scale means;

first and second indicator means for identifying individual numbers on said first and second scale means, respectively:

first selector means for moving said first scale means and said first indicator means with respect to each other so as to identify a number on said first scale means;

second selector means for moving said second scale means and said second indicator means with respect to each other so as to identify a number on said second scale means;

link means for moving one selector means in response to movement of the other; case means for encasing the device components, said case means including access windows disposed over said first and second scale means, and

multiplier means for adjusting the relative magnitudes of numbers displayed by said first and second scale means.

2. The combination in accordance with claim 1 further including calibration means for fixing the coupling between said link means and said first and second selector means whereby the distance traveled by one will be a fixed multiple of the distance traveled by the other, said first and second selector means each including overlapping, slotted arms having one end fixed at a point and the other end free to pivot about said point; said link means including a pin extending through the slots in both arms; and said calibration means including carriage means for restricting said pin to a straight line of travel disposed perpendicularly to an imaginary straight line passing through and connecting the pivot point of each arm.

3.- The combination in accordance with claim 2 wherein said carriage means includes an arm perforated by a guide slot, said guide slot embracing said pin and having an elongated shape to define said line of travel.

4. The combination in accordance with claim 3 wherein said carriage means includes adjusting means for laterally positioning said guide slot between the pivot points of said arms.

5. The combination in accordance with claim 4 wherein said adjusting means includes a worm drive terminated in an adjusting knob and said carriage means includes at least one opening tapped to accept said worm drive.

6. The combination in accordance with claim wherein said first selector means includes a drive mechanism for imparting movement to its associated arm.

7. The combination in accordance with claim 6 wherein said drive mechanism includes a drive block attached to said associated arm adjacent to its pivot point.

8. The combination in accordance with claim 7 wherein said drive block is supported by a worm drive.

9. The combination in accordance with claim 8 wherein said worm drive is longitudinally disposed in register with the worm drive assocaited with said adjusting means.

10. The combination in accordance with claim 9 wherein said guide slot is disposed between said carriage means and said drive block.

11. The combination in accordance with claim 4 wherein said first and second indicator means are included on said first and second selector means and said first and second scales are inscribed on a fixed base.

12. In a calculating device for converting numers from one number system to another, the combination comprising:

first and second graduated scale means inscribed on overlapping first and second rotating disks, respectively; I

stationary first and second indicator means for identifying individual numbers on said first and second scale means, respectivly:

first selector means for rotating said first scale means unitl said first indicator means identifies a preselected number thereon;

second selector means for rotating said second scale until said second indicator means identifies a preselected number thereon;

link means for moving one selector means in response to movement of the other, said link means including an inner and outer hub extending through the center of said first and second rotating disks;

calibrator means for fixing the coupling between said link means and said first and second selector means whereby the distance traveled by one will be a fixed multiple of the distance traveled by the other; case means for encasing the device components, and

multiplier means for adjusting the relative magnitude of numbers displayed by said first and second scale means.

13. The combination in accordance with claim 12 wherein each hub includes a spur gear and each selector means includes a curved and mating rack gear affixed to an arm.

14. The combination in accordance with claim 13 wherein each arm has two legs joined at one end to form a U-shaped configuration; one leg being slotted, the other leg terminating in said rack gear and said pivot point being located adjacent to the point of joiner between said two legs.

15. The combination in accordance with claim 14 wherein one of said arms includes a worm driven system for imparting pivotal movement thereto, said system being operative in response to rotation of an exteranl adjusting knob.

16. Th combination in accordance with claim 15 wherein said multiplier means adjusts the magnitude of numbers displayed in orders of ten.

17. The combination in accordance with claim 16 wherein said multiplier means includes two cover plates overlapping said first and second scales, respectively, and motor means for reciprocally translating said cover plates so as to cover and uncover digits displayed on said first and second scales.

18. The combination in accordance with claim 17 wherein said motor means includes a ped attached to each cover plate and said case includes serrated slots for holding said pegs in predetermined positions therein whereby the relative positions of said cover plates can be adjusted within said case.

19. In a calculating device for converting numbers from one system to another, the the combination comprisng:

case means for encasing components, said case means having access windows therein; first and second graduated scales inscribed on first and second overlapping rotating disks, respectively, said disks being located in said case with portions of said scales positioned beneath said windows; first and second indicator means for identifing numbers on said first and second scales, respectively;

first selector means for rotating said first disk beneath said first indicator means to identify a predeterrnined number thereon;

second selector means for rotating said second disk beneath said second indicator means to identify a predetermined number thereon;

link means for moving one selector means in response to movement of the other, said link means having a slotted link arm joing said first and second selector means and including a pivot pin extending through the slot in said link arm;

calibration means for fixing the coupling between said link arm and said first and second selector means whereby the distance traveled by one will be a fixed multiple of the distance traveled by the other, said calibration means including restraining means for confining the travel of the ends of said link arm to two parallel paths;

regulating means for adjustably positioning said pivot pin on a path disposed between and perpendicular to said two parallel paths, and

multiplier means for adjusting the relative magnitude between numbers displayed on said first and second scale means beneath said indicator means.

20. The combination in accordance with claim 19 wherein said link arm includes two independent ends each having an internal slot with one being slidably disposed within the other.

21. The combination in accordance with claim 20 wherein said restraining means includes two parallel tracks cut through said case and each selector means includes a carriage having a portion extending through one of said tracks, said portion being attached to said link arm on one side of said case and said carriage being connected and to one of said disks on the other side of said case.

22. The combination in accordance with claim 22 wherein said multiplier means includes a pair of movable cover plates adapted to cover or expose selected portions of said graduated scales on said disks and said mounted in one of said tracks, each shuttle includes a rack gear and each disk includes a spur gear attached to one of said rack gears.

25. The combination in accordance with claim 24 wherein each carriage includes a shuttle serially mounted in one of said tracks, a spring loaded drum attached to said rotary disk and a line wrapped around said drum and attached at one end to said shuttle.

l i l 

1. In a calculating device for converting numbers from one number system to another, the combination comprising: first and second graduated scale means; first and second indicator means for identifying individual numbers on said first and second scale means, respectively: first selector means for moving said first scale means and said first indicator means with respect to each other so as to identify a number on said first scale means; second selector means for moving said second scale means and said second indicator means with respect to each other so as to identify a number on said second scale means; link means for moving one selector means in response to movement of the other; case means for encasing the device components, said case means including access windows disposed over said first and second scale means, and multiplier means for adjusting the relative magnitudes of numbers displayed by said first and second scale means.
 2. The combination in accordance with claim 1 further including calibration means for fixing the coupling between said link means and said first and second selector means whereby the distance traveled by one will be a fixed multiple of the distance traveled by the other, said first and second selector means each including overlapping, slotted arms having one end fixed at a point and the other end free to pivot about said point; said link means including a pin extending through the slots in both arms; and said calibration means including carriage means for restricting said pin to a straight line of travel disposed perpendicularly to an imaginary straight line passing through and connecting the pivot point of each arm.
 3. The combination in accordance with claim 2 wherein said carriage means includes an arm perforated by a guide slot, said guide slot embracing said pin and having an elongated shape to define said line of travel.
 4. The combination in accordance with claim 3 wherein said carriage means includes adjusting means for laterally positioning said guide slot between the pivot points of said arms.
 5. The combination in accordance with claim 4 wherein said adjusting means includes a worm drive terminated in an adjusting knob and said carriage means includes at least one opening tapped to accept said worm drive.
 6. The combination in accordance with claim 5 wherein said first selector means includes a drive mechanism for imparting movement to its associated arm.
 7. The combination in accordance with claim 6 wherein said drive mechanism includes a drive block attached to said associated arm adjacent to its pivot point.
 8. The combination in accordance with claim 7 wherein said drive block is supported by a worm drive.
 9. The combination in accordance with claim 8 wherein said worm drive is longitudinally disposed in register with the worm drive assocaited with said adjusting means.
 10. The combination in accordance with claim 9 wherein said guide slot is disposed between said carriage means and said drive block.
 11. The combination in accordance with claim 4 wherein said first and second indicator means are included on said first and second selector means and said first and second scales are inscribed on a fixed base.
 12. In a calculating device for converting numers from one number system to another, the combination comprising: first and second graduated scale means inscribed on overlapping first and second rotating disks, Respectively; stationary first and second indicator means for identifying individual numbers on said first and second scale means, respectivly: first selector means for rotating said first scale means unitl said first indicator means identifies a preselected number thereon; second selector means for rotating said second scale until said second indicator means identifies a preselected number thereon; link means for moving one selector means in response to movement of the other, said link means including an inner and outer hub extending through the center of said first and second rotating disks; calibrator means for fixing the coupling between said link means and said first and second selector means whereby the distance traveled by one will be a fixed multiple of the distance traveled by the other; case means for encasing the device components, and multiplier means for adjusting the relative magnitude of numbers displayed by said first and second scale means.
 13. The combination in accordance with claim 12 wherein each hub includes a spur gear and each selector means includes a curved and mating rack gear affixed to an arm.
 14. The combination in accordance with claim 13 wherein each arm has two legs joined at one end to form a U-shaped configuration; one leg being slotted, the other leg terminating in said rack gear and said pivot point being located adjacent to the point of joiner between said two legs.
 15. The combination in accordance with claim 14 wherein one of said arms includes a worm driven system for imparting pivotal movement thereto, said system being operative in response to rotation of an exteranl adjusting knob.
 16. Th combination in accordance with claim 15 wherein said multiplier means adjusts the magnitude of numbers displayed in orders of ten.
 17. The combination in accordance with claim 16 wherein said multiplier means includes two cover plates overlapping said first and second scales, respectively, and motor means for reciprocally translating said cover plates so as to cover and uncover digits displayed on said first and second scales.
 18. The combination in accordance with claim 17 wherein said motor means includes a ped attached to each cover plate and said case includes serrated slots for holding said pegs in predetermined positions therein whereby the relative positions of said cover plates can be adjusted within said case.
 19. In a calculating device for converting numbers from one system to another, the the combination comprisng: case means for encasing components, said case means having access windows therein; first and second graduated scales inscribed on first and second overlapping rotating disks, respectively, said disks being located in said case with portions of said scales positioned beneath said windows; first and second indicator means for identifing numbers on said first and second scales, respectively; first selector means for rotating said first disk beneath said first indicator means to identify a predetermined number thereon; second selector means for rotating said second disk beneath said second indicator means to identify a predetermined number thereon; link means for moving one selector means in response to movement of the other, said link means having a slotted link arm joing said first and second selector means and including a pivot pin extending through the slot in said link arm; calibration means for fixing the coupling between said link arm and said first and second selector means whereby the distance traveled by one will be a fixed multiple of the distance traveled by the other, said calibration means including restraining means for confining the travel of the ends of said link arm to two parallel paths; regulating means for adjustably positioning said pivot pin on a path disposed between and perpendicular to said two parallel paths, and multiplier means for adjusting the relative magnitude between numbers displayed on said fIrst and second scale means beneath said indicator means.
 20. The combination in accordance with claim 19 wherein said link arm includes two independent ends each having an internal slot with one being slidably disposed within the other.
 21. The combination in accordance with claim 20 wherein said restraining means includes two parallel tracks cut through said case and each selector means includes a carriage having a portion extending through one of said tracks, said portion being attached to said link arm on one side of said case and said carriage being connected and to one of said disks on the other side of said case.
 22. The combination in accordance with claim 22 wherein said multiplier means includes a pair of movable cover plates adapted to cover or expose selected portions of said graduated scales on said disks and said indicator means includees an index mark located on each cover plate.
 23. The combination in accordance with claim 22 wherein each cover plate is attached to said case means by a pin and said case means includes a serrated track for holding said pins in predetermined positions whereby a multiplier function can be achieved by repositioning each pin within its track.
 24. The combination in accordance with claim 21 wherein each carriage includes a shuttle slidably mounted in one of said tracks, each shuttle includes a rack gear and each disk includes a spur gear attached to one of said rack gears.
 25. The combination in accordance with claim 24 wherein each carriage includes a shuttle serially mounted in one of said tracks, a spring loaded drum attached to said rotary disk and a line wrapped around said drum and attached at one end to said shuttle. 